Note: If you are driving these servos using the Arduino Servo library (or your own microcontroller code), then the high value of 180 (Arduino), which creates a 2.4ms pulse width, may be too high and tries to drive the servo past its mechanical end stop. This leads to a high current being drawn (1A+) and the servo gets hot. Reduce the Sketch value from 180 down to 170 and you should be ok